Biology subjects

Rooney, N.

Publications and source records attributed to Rooney, N..

3 recordsLinked to original sources

bioRxiv2024

Comparison of black soldier fly, cricket, and superworm on growth performance, nutrient utilization and fatty acid profiles of rainbow trout

Inclusion of fishmeal and fish oil in feeds for farmed fish is not sustainable and alternatives need to be evaluated. The aim of this study was to determine the effect of diets including defatted black soldier fly larvae (Hermetia illucens), adult cricket (Gryllodes sigillatus) and superworm (Zophobas morio) on the growth performance, apparent nutrient digestibility, nutrient retention, and fatty acid profiles of juvenile rainbow trout (Oncorhynchus mykiss). Triplicate tanks of fish (100.5 {+/-} 0.6 g; mean {+/-} SD) were fed one of four diets, a control diet with 20% fishmeal, and three experimental diets containing either 15% defatted black soldier fly meal, 15% full-fat adult cricket meal or 15% full-fat superworm meal, where each insect meal partially replaced fishmeal and fish oil. After 84 days of feeding, no significant differences were observed between diets for growth performance indicators or body indices. Fish fed the control and superworm diets had a higher protein content and retention in whole-body carcass compared to the cricket and black soldier fly diet groups. No significant effects between diets were found on whole-body carcass regarding fatty acid classes SFA, MUFA, PUFA n-3 and PUFA n-6, although lauric acid and myristic acid were significantly higher in fish fed black soldier fly diet and linoleic acid was higher in fish fed superworm and cricket diets. Retention of fatty acids was higher for most classes in fish fed the black soldier fly diet, yet whole carcass lipid content did not differ significantly between diets. Additionally, apparent digestibility of phosphorous was significantly improved for all insect diets compared to the control. These results indicate that insect meals can partially replace fishmeal and fish oil in diets for rainbow trout without compromising growth performance and fatty acid composition, while improving phosphorous utilization.

physiology↗

bioRxiv2024

Metabolic adaptations of micrometastases alter EV production to generate invasive microenvironments

Altered cellular metabolism has been associated with acquisition of invasive phenotypes during metastasis. To study this, we combined a genetically engineered mouse model of mammary carcinoma with syngeneic transplantation and primary tumour resection to generate isogenic cells from primary tumours and their corresponding lung micrometastases. Metabolic analyses indicated that micrometastatic cells increase proline production at the expense of glutathione synthesis leading to a reduction in total glutathione levels. Micrometastatic cells also have altered sphingomyelin metabolism leading to increased intracellular levels of specific ceramides. The combination of these two metabolic adaptations alters small extracellular vesicle (sEV) production to drive generation of an invasive microenvironment. Indeed, micrometastatic cells shut-down Rab27-dependent production of sEVs and, instead, switch-on neutral sphingomyelinase-2 (nSM2)-dependent sEV release. sEVs released in a nSM2-dependent manner from micrometastatic cells, in turn, influence the ability of fibroblasts to deposit extracellular matrix which promotes cancer cell invasiveness. These data provide evidence that metabolic rewiring drives invasive processes in metastasis by influencing sEV release. SummaryBreast cancer cells isolated from lung micrometastases have altered metabolism which influences extracellular vesicle production to generate invasive microenvironments.

cancer biology↗

bioRxiv2022

Cryo-EM structure of the Agrobacterium tumefaciens T-pilus reveals the importance of positive charges in the lumen

Agrobacterium tumefaciens is a natural genetic engineer that transfers DNA into plants and this is the most frequently applied process for the generation of genetically modified plants. DNA transfer is mediated by a type IV secretion system localized in the cell envelope and extracellular T-pili. We here report the cryo-electron microscopic structures of the T-pilus at 3.2[A] resolution and that of the related plasmid pKM101-determined N-pilus at 3[A] resolution. Both pili contain a main pilus protein (VirB2 in A. tumefaciens and TraM in pKM101) and phospholipids arranged in a 5-start helical assembly. They contain positively charged amino acids in the pilus lumen and the lipids are positively charged in the T-pilus (phosphatidylcholine) conferring overall positive charge to the lumen. Mutagenesis of the lumen-exposed Arg91 residue in VirB2 resulted in protein destabilization and loss of pilus formation. Our results reveal that different phospholipids can be incorporated into type IV secretion system pili and that the charge of the lumen is of functional importance.

biochemistry↗